How to use “grep” & “vim” , “ which”

     [1]. How to use “grep” command to find text including subdirectories

           grep -rnw '/path/to/somewhere/' -e 'pattern'
  • -r or -R is recursive,
  • -n is line number, and
  • -w stands for match the whole word.
  • -l (lower-case L) can be added to just give the file name of matching files.
     [2]. which command

            which [filename1] [filename2] ...

     [3]. Vim
            
  • x - to delete the unwanted character
  • u - to undo the last the command and U to undo the whole line
  • CTRL-R to redo
  • A - to append text at the end
  • :wq - to save and exit
  • :q! - to trash all changes
  • dw - move the cursor to the beginning of the word to delete that word
  • 2w - to move the cursor two words forward.
  • 3e - to move the cursor to the end of the third word forward.
  • 0 (zero) to move to the start of the line.
  • d2w - which deletes 2 words .. number can be changed for deleting the number of consecutive words like d3w
  • dd to delete the line and 2dd to delete to line .number can be changed for deleting the number of consecutive words

Comments

Post a Comment

Popular posts from this blog

Java : Variables Declaring

[1]. Java Variables Variables are containers for storing data values. In Java, there are different types of variables, for example: String - stores text, such as "Hello". String values are surrounded by double quotes int - stores integers (whole numbers), without decimals, such as 123 or -123 float - stores floating point numbers, with decimals, such as 19.99 or -19.99 char - stores single characters, such as 'a' or 'B'. Char values are surrounded by single quotes boolean - stores values with two states: true or false [2]. Declaring (Creating) Variables To create a variable, you must specify the type and assign it a value: Syntax type variable = value ; Where type is one of Java's types (such as int or String), and variable is the name of the variable (such as x or name). The equal sign is used to assign values to the variable. To create a variable that should store text, look at the following example: Example Create a variable called  name  of type  Stri...
Read more

Install DNF in RHEL/CentOS 7

  Install DNF in RHEL/CentOS 7 DNF stands for Dandified yum. DNF is a software package manager for RPM-based Linux distributions such as Fedora, RHEL and CentOS. It is the next upcoming major version of Yum. DNF is first introduced in Fedora and has replaced to become the default package manager of the Fedora distributions. DNF is same as Yum that installs, updates and removes packages on RPM bas4ed Linux systems. DNF is introduced for improving the bottlenecks of Yum such as performance, Memory usages, Dependency resolution, speed, and some other factors. The latest stable release of DNF is 1.0 and it is written in Python.   Installation of DNF in RHEL/CentOS 7 1) To install DNF on RHEL/CentOS 7 systems, you need to set up and enable epel YUM REPO before installing DNF. # yum install epel-release 2) Install DNF # yum install DNF 3) You can now start to run commands using DNF. To view the man page you can use the following command: # dnf –help
Read more

SQL Self JOIN

SQL Self JOIN A self JOIN is a regular join, but the table is joined with itself. Self JOIN Syntax SELECT column_name(s) FROM table1 T1, table1 T2 WHERE condition; T1 and T2 are different table aliases for the same table.
Read more